As currently implemented, the designProcedureByExample API call does not support procedures which do not have an explicit OUT cursor (for example, DB2 stored procedures using RESULT SETS instead).
In this situation, the procedure will error out with a NULL value. This severely restricts the types of output generating procedures that can be used with this API call.
In order for the designProcedureByExample API to work efficiently for all types of procedures, please update this API call to silently handle this use case (e.g by implicitly creating an OUT CURSOR when one does not exist).